Daily washing of the face skin is one of the primary hygienic procedures of a present-day human. Water is one of the main components of the face skin washing procedure. In developed countries people use water from centralized water supply sources for the washing procedure. Due to the important hygienic role of water its quality is rigorously standardized and controlled. Table 1 lists the main hygienic parameters of water established by Russian Federation. European Union. the USA and the World Health Organization (WHO) for centralized water supply sources.
The standards listed below are justified when applied to potable water; however, they are not suitable if the water in question is used for washing of skin.
The surface skin level is known to have a weak-acid pH reaction within the range of 4.0-6.0 (Analysis of circadianand ultradian rhythms of skin surface properties of face and forearm of healthy women. Le Fur l. Reinberg A., Lorez S., Morizot F., Mechkouri M.. Tschachler E., J. Invest Dermatol, 2001, September, 117:3, pp. 718-724). Problem skin can have the pH parameter shifted in the alkaline direction. This is caused by perspiration disorders in the skin folding regions, activity of certain bacteria and several other factors (Baseline biophysical parameters in subjects with sensitive skin, Seidenari S., Francomano M., Mantovani L., Contact Dermatits, 1998, June, Vol. 38, pp. 311-315). Common hygienic procedures can alter the pH level of skin, too. For example, after three minutes of washing the skin with soap its pH level is shifted in the direction of weak-alkaline values, whereupon at least three or four hours are required for the skin to restore its normal acidity. Even simple washing of the face skin bat means of water with almost neutral acidity parameter (thermal water common tap water, water purified by means of ion-exchange resin or reverse osmosis system) results in prolonged increase of skin acidity level above pH 6.0. This weakens the antimicrobial parameters of skin, which, in particular, is a consequence of inhibition of the normal microflora of skin that happens when the pH parameter is shifted to the direction of neutral and alkaline values; other consequences are the swelling of the skin, accelerated formation of microcrystals of salts that damage the skin, disorders of the epidermis cells functioning (Effects of soap and detergents on skin surface pH, stratum corneum hydration and fat content in infants, Gfatter R., Hackl R., Braun F., Dermatology, 1997, Vol. 195, pp. 258-262).
After washing the skin with hard water its surface accumulates salts of calcium, magnesium and ferrum that are formed in hard water when the ions of calcium, magnesium and ferrum interact with soap. Such salts are not soluble in water, and their crystals seriously damage the skin. The hardness of water can be reduced by boiling, freezing-out, purification by means of ion-exchange filters or reverse osmosis, but the resulting water has reduced osmotic pressure (hyposmolarity).
Table 2 gives the indices of water purification provided by the RO-(reverse-osmosis) membrane.
The use of hyposmolar deionized water during hygienic procedures results in violation of the colloid structure of the epidermis and the protective water-lipidic mantle.
Another important consequence of violation of physiological level of the skin pH is the chemical blockade of amino acids that takes place upon increase of the pH level of skin and disrupts its hydration (Damage to the skin by repetitive washing, Grunewald A. M., Gloor M., Gehring W., Kleesz P., Contact Dermatitis, 1995. Vol. 32, pp. 225-232).
Some known methods of washing the face skin consist in applying shampoo and water (see GB, A1, 908888) or soap and water (see CN, C, 1425749).
Another known method of washing the skin of the face and other areas consists in using soap and common water with pH level that is close to the neutral value (see U.S. Pat. No. 6,559,110).
This engineering solution is taken as a prototype of the current invention—method.
Soap contains substances intended for adjusting the pH level of the skin. The disadvantage of the prototype and other analogous inventions mentioned above consists in that the washing or cleaning agent quickly becomes diluted with water, whereupon its pH level changes from the range of acid values 2.0-6.0 to the neutral direction. The pH of the surface layer of skin also becomes close to neutral value, within the range of 6.0-7.0 pH.
Mineral thermal waters are generally known, such as for example the Vichy thermal water, which has the following properties: calming effect on sensitive skin, anti-edematous and anti-hyperemic effects. Such water reinforces the protective functions of skin and is used in the morning and evening for finishing the hygiene of sensitive face skin, and also during the day as a refreshing agent; the water is sprayed upon the face and then dried with a tissue.
The disadvantage of this water consists in its high mineralization (over 5 g per 1 litre of water). The main components of the mineralization are magnesium, potassium, sodium, manganese and ferrum.
Another widely known thermal water is the thermal water “Laboratoires Biorga” (France). Such water is recommended for daily use for sensitive and hypersensitive skin of newborns, children and adults. The Uriage thermal water, natural isotonic water, is also widely known. It is in perfect osmotic balance with the epidermis cells and their natural medium. Unique concentration of mineral elements makes the Uriage water an excellent agent for treating the face skin: it calms the skin, reduces redness, moisturizes upper layers of epidermis and reinforces natural protective mechanisms of skin. The water is sprayed upon the face skin.
The disadvantage of this water consists in high percentage of calcium and magnesium ions, and in its near neutral pH level.
Thus, the provided data show that the general disadvantage of thermal waters consists in high mineralization and non-physiological pH, which doesn't allow using them as agents for washing the face skin. As a result, thermal waters are used mostly for hydration of the face skin.
Another known application of thermal water consists in using it for reducing the side effects of keratolytic agents incorporated therein (see RU, C. 2131254).
During washing of the skin the oxygen contained in the skin is depleted, the amino acid and microbiological balance of skin is broken. The amount of oxygen dissolved in the water plays an important part in maintaining normal metabolic processes in upper layers of epidermis. The water used in central water supply has low content of dissolved oxygen. This is caused by various reasons: the water is taken either from underground (artesian) layers where the water has low oxygen content from the beginning, or from surface reservoirs with low purity level. Further loss of oxygen takes place during transportation of water through the piping and is caused by oxidation of ferrum and other chemical components of water and the piping system. The use of water with low content of oxygen for daily hygienic procedures may result in intensification of anaerobic processes in the epidermis cells and the microbial colonies of the skin, which is not natural for normal skin.
Amino acids are formed from the keratin of the corneal layer dissolved in water. Amino acids represent one of the main components of the so called Natural Moisturizing Factor. Ionization of the majority of essential amino acids at pH>6.0 results in disorder of their circulation in the surface layers of skin; the washing-off of the amino acids disrupts the hydration and the buffering properties of the skin.
Thus, the process of washing the face skin comprises serious and versatile chemical, biochemical and biological alterations in surface layers of the face skin. Constant influence of this factor can deplete adaptation capabilities of surface layers of skin, resulting in cosmetic defects, diseases of skin and accelerated skin ageing.
A known composition for washing the face skin comprises sodium laureth sulphate, cocamidopropylbetaine, laurylglucoside, PEG-7, glyceryl cocoate, moisturizing admixtures, 40% solution of NTO-55 propyleneglycololeate in propyleneglycol, PEG-40, hydrogenated castor oil, disodium salt ethylenediamine —N,N,N,N,— of 2-water tetraacetic acid, extra or first-class edible citric acid, germabene II. perfume composition, colorants and potable water, bioactive supplements and triclosan, distilled glycerin or propyleneglycol (see RU, C, 2179844).
This composition has an irritating and allergenic influence upon the skin; the detergents adsorbed on the skin surface during the washing prevent normal regeneration of integrity of the protective water-lipidic mantle. This results in increased sensitivity of skin towards negative effects of ultraviolet radiation. The antiseptics contained in the composition strike not only pathogenic and opportunistic pathogenic microorganisms, but also microorganisms that form part of the normal microflora of skin. In natural conditions the normal microflora of skin has an inhibitory effect on the development of microorganisms that are alien for it. Skin that is damaged during the washing and has disturbed microbial balance becomes especially sensitive towards infection with alien microorganisms, including microorganisms contained in the water that is used for washing the face skin.
Another known composition for washing the face skin is produced by dissolving a suspension of deer's placenta in boiled water with subsequent quick freezing and thawing (see CN, 1221606).
The disadvantage of this water consists in its non-physiological pH, which is near the neutral level. Regular use of this water leads to alkalization of the face skin surface.
Yet another known composition for washing the face skin comprises water, mineral salts and dissolved oxygen, and has the capacity of increasing the content of oxygen in the face skin (see DE, A1, 4236607). The composition constitutes a water emulsion that contains from 1 to 8% of weight of nonionic surfactant as an emulsifier and from 0.05 to 100% of weight of oxygen-binding fluorocarbon compounds.
This engineering solution is taken as a prototype of the current invention—composition.
The disadvantage of said composition consists in toxicity and low stability of fluorocarbon compounds, inhibition of energy metabolism of the skin cells, which is caused by the presence of fluorocarbon compounds (Riess J. G., Rev. Fr. Transfus Hemobiol. 1992, Vol. 35, p.p. 391-406; Faradji., et. al., Rev. Fr. Transfus Immunohematol, 1979, Vol. 22, p.p. 119-133: Reichlet H., et. al., Biomater Artif Cells Immobilization biotechnol, 1992, Vol. 20, p.p. 1021-1023). Furthermore, said composition neither provides the required pH values for the face skin nor supports the amino acid and microbiological balance of the face skin.